Vehicles, such as automobiles, include bumper assemblies at a front and/or at a rear of the vehicle. The bumper assembly may include a bumper beam that may plastically deform upon impact during a collision between the vehicle and another object. A fascia may cover the bumper beam and provide an aesthetic appearance.
The vehicle includes a frame having a rail. The bumper beam may be supported on the rail with crash cans, which connect to the bumper beam and to the rail. The crash cans are configured to crumple, and thus absorb energy, when subjected to compressive forces between the bumper beam and the rail during a collision between the vehicle and another object. The crash cans are fixed to the bumper beam and the rail and, as such, when the crash cans are crumpled during a collision, the rail of the frame must be replaced in order to provide new crash cans.
The material of each crash cans builds up as the crash can crumples during the collision. Some collisions of certain magnitudes may fully collapse the crush cans, i.e., the material of the crash can builds up to a point such that built-up material prevents further collapse of the crash cans. For example, a typical crash can, when fully compressed, are still 70-80% of the pre-compressed length of the crash can. When the crash can is fully collapsed, further movement of the bumper beam during the collision may cause the crash can and/or the bumper beam to pierce through the fascia. In such situations the fascia must be replaced. Such replacement is costly and negatively affects the rating of the vehicle during a low speed damageability (LSD) test. The LSD test measures the amount of damage to a vehicle during a low speed and damage to the body, sheet metal parts, etc., requiring replacement of these components is unfavorable to the results of the LSD test.
In addition, the stacked up material of the crash can spaces the bumper beam from the rail. However, for aesthetic purposes, some vehicles are designed with tight packaging constraints in the bumper assembly, e.g., low profile bumper assemblies. This stacked up material may not conform with these tight packaging constraints in the bumper assembly.
As such, there remains an opportunity to design an improved energy absorber that absorbs energy between the rail and the bumper beam and fits within tight packaging constraints.